JPS6253946A - Production of p-phenylenediamine - Google Patents

Abstract

PURPOSE:To obtain the aimed substance, by subjecting aniline to diazo coupling reaction and acid-rearrangement reaction, adding on alkali to an aniline solution of thus obtained p-aminoazobenzene, separating an oil layer from a water layer, adding a water to the separated oil layer and subjecting the oil layer to hydrogenolysis. CONSTITUTION:An alkali is added to an aniline solution of p-aminoazobenzene, obtained through diazo coupling reaction and acid-rearrangement reaction of aniline, to adjust pH of a water layer within 7.0-13.8 (preferably 8.0-12.0), and an oil layer is separated from the water layer. 0.05-5.0pts.wt. (preferably 0.10-1.0pts.wt.) (based on 1pts.wt. oil layer) water is then added to the oil layer and mixed therewith to obtain an emulsion or suspension. The product is passed through a filter and allowed to stand to separate the oil layer, and the oil layer is subjected to hydrogenolysis reaction in the presence of a reducing catalyst to obtain the titled substance. USE:A raw material for heat-resistant wholly aromatic polyamides or a raw material for dyes, rubbers, chemicals, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing K-Lp-phenylenediamine by catalytic hydrogenolysis of p-7477zobenzene. More specifically, a 7=phosphorus solution of p-7i noazobenzene obtained by a diazotization coupling-acid rearrangement reaction of aniline is hydrogenolyzed in the presence of a reduction catalyst to produce p-phenylenediamine. Regarding how to

p-Phenylenediamine has been used for a long time in the dye industry and the rubber chemical industry, and has recently been used as a raw material for heat-resistant wholly aromatic polyamides, and has important industrial uses.

(Prior art) Aniline is subjected to diazotization coupling, and then p-7Zno7zobenzene is converted into 7. A method for producing p-phenylenediamine by obtaining a phosphorus solution and subjecting it to catalytic hydrogenolysis is well known. This reaction formula is shown below.

NH2NH2 In this case, the reaction is generally carried out with an excess of aniline, so that p-aminoazobenzene is obtained as an aniline solution, and this is directly subjected to the hydrogenolysis reaction, so that aniline is produced as a by-product. This is an industrially preferable embodiment considering that.

By the way, when p-aminoazobenzene synthesis is actually synthesized from aniline and p-phenylenediamine is synthesized by t-hydrogenolysis of aniline solution, the organic layer is simply separated from the aqueous layer from the reaction mixture of +7i-7zobenzene. If it is directly subjected to a hydrogenolysis reaction, good results will not be obtained. In this case, it is necessary to remove at least the acid used as a catalyst for the rearrangement reaction, but it is not easy to remove the acid, so it is necessary to make the hydrogenolysis reaction proceed smoothly. Various treatment methods have been devised to obtain good results. For example, JP-A-54
-52035 is obtained by separating the p-7i minofujibenzene formation reaction mixture obtained by synthesis from aniline into an aqueous layer and an organic layer, and adding a specified amount of mineral acid to this organic layer,
A method for suppressing side reactions in the hydrogenolysis reaction of p-757 azobenzene by adding an aniline salt of a mineral acid is disclosed.

Furthermore, in order to remove the acid from the rp-74-7zobenzene synthetic solution, it is possible to wash it with water to remove the acid, but the reaction between the p-7i minoazobenzene solution and neutral water is extremely Separability is poor and impractical. Therefore, neutralization washing with a dilute alkaline aqueous solution is performed, but with this method, the yield of p-phenylenediamine in the hydrogenolysis reaction varies greatly, and it is not always possible to "Not being able to get good results."

The following methods can be used to eliminate variations in the yield of p-phenylenediamine and improve performance.

(2) A method in which an aniline solution of p+74 noazobenzene is used after separating the aqueous phase and allowing it to stand still for a long period of time (for example, one week).

(2) A method in which the aniline solution of p-aminoazobenzene, which has been washed with an alkali and the aqueous layer has been separated, is further dehydrated.

A method of treating powdered activated carbon instead of dehydrating θ　O.

However, all of these methods are insufficient industrially, and as an improved method, a small amount of p-aminoazobenzene synthesis aniline solution is added to the aniline solution for p-aminoazobenzene synthesis after alkaline washing and separation. A method of adding mineral acids or aniline salts of mineral acids to suppress gt+ reactions has been shown.

However, in the method shown in JP-A-54-52035, the effect differs depending on the amount of mineral acid or acid aniline salt added, and the required amount of addition is It varies depending on the history of the p-aminoazobenzene synthesis aniline solution, such as the reaction conditions during the 7zobenzene synthesis, the alkali concentration during the alkali washing, and the degree of water contamination during the oil/water separation operation, and is not necessarily constant. Therefore, it is complicated to deal with, and if the amount added is incorrect, good results cannot be obtained.

JP-A-57-122047 discloses p-
Maximum 6Wt as aminoazobenzene synthesis aniline solution
Approximately 500% dissolved in water and strong acids up to 96%
This method uses a material containing less than 7 ppm of ions and substantially no mixed free water.

The following is suggested as a means of achieving this.

(a) Separating the p-aminoazobenzene synthesis reaction mixture into an organic layer and an aqueous layer.

(-) After contacting the organic layer with an aqueous solution of [i] such as ammonium hydroxide, ammonium carbonate, and aluminum amine,
Separate into an organic layer and an aqueous layer.

In this method, as the alkali used for washing with water,
It is characterized by the fact that a weakly basic substance is selected, and when the apparatus is filled, it gives relatively stable results in the aqueous partial reaction of p+74-7zobenzene.

However, the separation between the organic layer and the aqueous layer is not necessarily good. Therefore, it is not easy to obtain a product substantially free of free water, which is a necessary factor for achieving effectiveness.

(Problems to be Solved by the Invention) In the method for producing p-phenylenediamine by subjecting a p-aminoazobenzene synthesized aniline solution synthesized from aniline to a hydrogenolysis reaction as described above, before subjecting it to aqueous decomposition, , p-aminoazobenzene synthesis It is necessary to process the aniline solution to allow the hydrogenolysis reaction to proceed smoothly.

Treatment methods include washing with water or a dilute alkaline aqueous solution, but in near-neutral conditions, liquid separation properties are extremely poor.

As the pH of the cleaning solution increases, the liquid separation properties are improved, but on the other hand, there is a contradictory problem in that the performance of the hydrogenolysis reaction becomes unstable.

There is also a method of stabilizing the results of the hydrogenolysis reaction by adding a specified amount of mineral acid or aniline salt of mineral acid to the p-7 mino-7zobenzene synthesized aniline solution after alkaline washing, but this method In this case, it is necessary to adjust the amount added according to the synthesis conditions and processing conditions of the p-7i minofujibenzene-containing aniline solution, and the added mineral acid may sometimes react with water and chromatography decomposition reaction and the same reaction solution. Affects equipment material corrosion in the processing process.

The present invention solves the problems in the prior art described above in a method for producing p-phenylenediamine by subjecting an aniline solution of p-aminoazobenzene synthesized from aniline to a hydrogenolysis reaction. Processing that simplifies processing operations and shortens processing time by improving liquid separation properties when processing synthetic aniline solutions ■ Hydrogenolysis reactions can be carried out without the use of special additives that may adversely affect material corrosion. We have developed a new processing method that simultaneously satisfies item 02 of a processing method that can proceed smoothly and stably obtain p-phenylenediamine in a high yield, and produce p-phenylene in a high yield suitable for industrial production. Provided is a method for producing diamine.

(Means for solving problems).

That is, in the present invention, an alkaline compound is added to an aniline solution of p-aminoazobenzene obtained by diazotization coupling and acid rearrangement reaction of aniline to adjust the pH to 7.0 to 1.
3.8, separate the oil layer and water layer, add 0.05 to 5.0 parts by weight of water per t weight part to the obtained oil layer, mix, and pass through a filter to separate the oil layer and water layer. This is a method for producing p-phenylenediamine by separating the resulting oil layer into hydrogenolysis in the presence of a reducing catalyst.

The synthesis of p-aminoazobenzene from aniline in the method of the present invention is carried out by conventional methods. That is, excess aniline and a diazotizing coupling agent (a combination of nitrite and mineral acid, or a mixed gas of nitrogen dioxide and nitrogen monoxide) are reacted and rearranged to synthesize p-aminoazobenzene.

An example of using sodium nitrite and hydrochloric acid as the diazotization coupling agent will be described below.

To synthesize p-aminoazobenzene from aniline, first add aniline hydrochloride to an aniline solution at 2 to 40°C (
It is preferably carried out at a temperature of 5 to 25°C by gradually adding a predetermined amount of an aqueous sodium nitrite solution.

Aniline is used in excess, HC8 is HCA/Na
The NO2 mo/l/ratio is 1.01 to 2.0, preferably 1
．． It is appropriately selected within the range of 1 to 1.4.

After adding a predetermined amount of the aqueous sodium nitrite solution, stirring is continued for a while to complete the diazotization coupling reaction and a slurry containing diazoaminobenzene crystals is obtained.

The reaction mixture was then heated under stirring for 50 min.
The temperature is raised to ~80°C to carry out a rearrangement reaction of diazoaminobenzene to p-aminoazobenzene. As the rearrangement reaction progresses, the diazoaminobenzene crystals disappear.

After the rearrangement reaction, the reaction mixture consists of an oil layer consisting of an aniline solution containing p-aminoazobenzene, by-produced 0-aminoazobenzene, and a small amount of water, and an aqueous layer containing salt and a small amount of aniline dissolved therein. There is. The liquid is acidic, and an alkaline compound or its aqueous solution is added and mixed to this mixture until the pH of the aqueous layer is 7.0 to 13.
8, preferably 8.0 to 12.0.

It also has the effect of reducing the amount of aniline dissolved in the aqueous layer by making the liquid alkaline.

After addition of the alkali, the mixture is allowed to stand at 20 to 40°C to separate into an oil layer and an aqueous layer.

In this liquid separation and two-layer separation operation, it is sufficient to simply perform static separation, but it is more preferable to carry out liquid separation after passing through a filter.

As the alkaline compound, caustic alkali such as caustic soda and caustic potash, alkali carbonate such as soda carbonate and potassium carbonate, alkali bicarbonate such as baking soda, etc. can be used.

0.05 to 5.0 parts by weight of the oil layer thus obtained (aniline solution of p-aminoazobenzene).
A basin of water corresponding to 0 parts by weight, preferably 0.10 to 1.0 parts by weight, is added and mixed. The amount of water to be added is determined as appropriate depending on the type and amount of the alkali compound used during alkalization and the conditions of the subsequent two-layer separation operation1.If the amount is too small, the effect will be low and hydrogen decomposition will occur. The reaction may not be smooth, and if there is too much, economic efficiency will be lost.

When water is added and mixed, the mixture usually becomes emulsified or suspended, and does not easily separate into an oil layer and an aqueous layer even if left standing. In the present invention, this mixture is passed through a filter at a temperature of 20 to 40°C, and then left to stand to separate into an oil layer and an aqueous layer.

As mentioned above, the mixture of the p-aminoazobenzene synthesized aniline solution and water has extremely poor liquid separation properties, but surprisingly, once it is passed through a filter, the liquid separation properties become extremely good. For example, it would take several days to completely separate the oil and aqueous layers by simply leaving the mixture to stand still.If the mixture is passed through a filter and left to stand still, it will be possible to separate the liquid into two layers in an extremely short time. .

Various materials can be used for the filter, but filters containing glass fibers are particularly effective in increasing the branching properties and are therefore preferred.

The method of separating the liquids after passing through a filter not only improves the separation properties between the oil layer and the water layer, but also eliminates forms such as turbidity in the resulting oil layer compared to the case of simple static separation. There are few free water droplets. In addition, there is significantly less contamination of substances that are likely to be mixed in with free water and have an adverse effect on hydrogenolysis.

The oil layer obtained in this way is an aniline solution of p-aminoazobenzene and 0-aminoazobenzene, which is subjected to the hydrogenolysis reaction described above to cause a contact reaction with hydrogen in the presence of a reducing catalyst. , p- and 0-aminoazobenzene are subjected to hydrogenolysis reactions.

A palladium catalyst or a nickel catalyst is used as the reduction catalyst. These catalysts are prepared by supporting a palladium component or a nickel component on a support inert to the reaction, such as carbon, silica, alumina, and diatom.

Typical examples of commercially available catalysts include 0.5wt% palladium-supported carbon, 0.5wt% palladium-supported alumina grains, 0.5wt% palladium-supported silica grains (all manufactured by Nippon Engelhard), and nickel catalyst N- 103, nickel catalyst N-111, nickel catalyst N-113 (all manufactured by JGC Chemical Co., Ltd.), and pulverized products thereof. It is also possible to use a palladium catalyst and a nickel catalyst together.

The hydrogenolysis reaction can be carried out under a wide range of temperature and pressure conditions, but is usually 40 to 200°C, preferably 1
Temperature of 00-180℃, 2-100klI/cI/lG
1 Preferably a pressure of s-5-2 o/dG is used.

The hydrogenolysis reaction of the present invention can be carried out either batchwise or continuously.

(Effect of the invention) When the hydrogenolysis reaction of p-aminoazobenzene is carried out using the aniline solution of p-aminoazobenzene treated by the method of the present invention, the reaction proceeds extremely smoothly.
p-Aminoazobenzene can be synthesized stably and in high yield.

(Example) Example 1 (A) Synthesis of p-aminoazobenzene Aniline 744M (8.0 mol) was charged into a 214-round flask equipped with a stirrer, a thermometer, and a dropping funnel, and the temperature was raised to 20°C or higher while stirring. 3 while cooling so that it does not rise.
125 t (1.2 mol) of 5% aqueous hydrochloric acid solution was added.

After adding the entire amount of hydrochloric acid, continue adding 69.0f of sodium nitrite (
An aqueous solution of 1.0 mol) dissolved in 130 tons of water was heated at 20°C.
The mixture was added dropwise over about 1 hour while stirring while maintaining the temperature below. After the dropwise addition was completed, stirring was continued for an additional 15 minutes at 20°C, and a liquid containing a large amount of yellow slurry was obtained.

Next, the temperature was raised to 50°C over 20 minutes, and a rearrangement reaction was carried out at 48 to 50°C for 1 hour. The reaction solution became a reddish-brown homogeneous solution. In order to complete the reaction, the temperature was further raised to 70°C and stirred for 15 minutes to complete the reaction.

The pH of the aqueous phase of the reaction mixture was 4.5.

e After cooling the reaction mixture obtained in the treatment before hydrogenolysis of the p-aminoazobenzene synthesis solution, 55 wt% Na
The pH was adjusted to 9.0 by adding an OH aqueous solution, and then the mixture was allowed to stand to separate the aqueous layer and the oil layer. An oil layer 776f was obtained.

When 510 f of water was added to this oil layer and mixed, an emulsified mixture was formed, which did not easily separate into an oil layer and an aqueous layer even when left to stand.

Next, a glass tube with an inner diameter of 15 mm and a slightly tapered tip was prepared with glass wool tightly packed to a height of approximately 5 mm, and the emulsified mixture was passed through this column at normal pressure and room temperature. did.

The mixture that passed through the glass wool layer was separated into a reddish brown oil layer and an aqueous layer to obtain oil FtJ (aniline solution of p-aminobenzene and 0-aminoazobenzene) 7701.

According to gas chromatography analysis, the p-aminoazobenzene concentration in the liquid was 23.1 wt%, and the 0-aminoazobenzene concentration was 2.0 wt%.

The yield of p-aminoazobenzene based on the sodium nitrite charge was 90.2%, and the yield of 0-aminoazobenzene was 7.8%.
become.

0 Oil layer obtained in synthesis (B) of p-phenylenediamine by hydrogenolysis of p-aminoazobenzene (aniline solution of p-aminoazobenzene) 60. Of was sampled within 10 minutes after branching and placed in a stainless steel 200d electromagnetic stirring autoclave. To this was added 0.596pd-carbon granular catalyst (manufactured by Nippon Engelhardt Co., Ltd.), which was ground into powder, and 0.14f (PD: approximately 50ppm relative to p-aminoazobenzene), sealed, and left at room temperature. After replacing the internal air with hydrogen, the pressure becomes 1゜0 kg/c.
Hydrogen was charged so that it became dG. Next, the cyanote crepe was heated with a heater to raise the temperature of the contents. When the temperature of the contents reached 115° C., hydrogen was supplied so that the pressure became 7 kg/cdG, and stirring was started to start the reaction.

After the reaction starts, the reaction temperature is maintained at 120°C, and the same amount of hydrogen as consumed by the reaction is replenished to raise the hydrogen pressure to 7.
The reaction was carried out while maintaining the ratio between 0 and 9/cdG.

The reaction was terminated when no more hydrogen was absorbed. The reaction time was 50 minutes.

After the reaction was completed, the reaction product was taken out, diluted with ethanol, and the catalyst was separated from P. The autoclave and the catalyst were washed with ethanol, and the P solution and this washing solution were combined to make the reaction product solution entirely in ethanol. Analysis of this solution by gas chromatography revealed that the conversion rate of p-aminoazobenzene and 0-aminoazobenzene was 10,096. Also, p-phenylenediamine 7,45f, and 0-phenylenediamine 0
．． 6Of was generated.

This is a p-phenylenediamine yield of 98.0% based on p-aminoazobenzene present in the solution used for hydrogenolysis, and an 0-phenylenediamine yield of 91.2% based on 0-aminoazobenzene. Corresponds to %.

This result corresponds to a yield of 88,496% for p-phenylenediamine and 7,196% for 0-phenylenediamine, for a total of 95.5%, based on sodium nitrite.

Comparative Example 1 (removal of aqueous layer from p-aminoazobenzene reaction mixture and hydrogenolysis) p-aminoazobenzene was synthesized using the same charging ratio and under the same conditions as in Example 1 (2). When the reaction mixture was allowed to stand still, it was separated into two layers, and an oil layer 784f and an aqueous layer 285t were obtained.

According to gas chromatographic analysis, the concentration of p-aminoazobenzene in the oil layer was 22.7 wt%, and the concentration of 0-aminoazobenzene was 2.0 wt96.

The yield based on sodium nitrite is p-aminoazobenzene 9
0.296, o-aminoazobenzene 7.8%, total
It is 98.0%.

■This oil MjJ 60. Of course, a hydrogenolysis reaction was carried out under the same conditions as in Example 1 and (Q). It took 5 hours and 35 minutes for hydrogen absorption to disappear, and the color of the reaction liquid was purple-blue.

Gas chromatographic analysis showed that almost no p-aminoazobenzene remained, but the yield of p-phenylenediamine based on the charged p-aminoazobenzene was 64.
It was 0%.

Comparative Example 2 (Removal of water layer from p-aminoazobenzene reaction mixture, washing of oil layer with water, and hydrogenolysis) (2) Oil layer obtained in Comparative Example 1 (A) 200. Take Or and add 80. Of water was added, and the mixture was shaken using a separating rotor and left to stand to separate oil and water.

Even after 6 hours of standing, an intermediate layer was present in addition to the oil and water layers, and oil-water separation was insufficient. 150 excluding water layer and middle layer
．． An oil layer of Of was obtained.

The concentrations of p-aminoazobenzene and 0-aminoazobenzene in the oil layer were 25.5 wt% and 2.0 wt%, respectively.

■Oil layer obtained from prisoners 60. Of was taken, and a hydrogenolysis reaction was carried out in the same manner as in Example 10. The reaction took 5 hours and 20 minutes. Conversion rate of p-aminoazobenzene is 100%
However, the p-phenylenediamine yield based on the charged p-aminoazobenzene was 83.2%.

Comparative Example 3 (p-aminoazobenzene reaction mixture) A synthesis reaction of p-aminoazobenzene was carried out at the same charging ratio and under the same conditions as in Example 1^.The resulting reaction mixture was cooled,
A 35 wt % NaOH aqueous solution was added to adjust the pH to 9.0, and then the mixture was allowed to stand to separate the water layer and the oil layer. As a result, oil layer 7762 was obtained. The p-aminoazobenzene concentration in the oil layer was 22.9wt%, and the o-aminoazobenzene concentration was 2.0wt%.

■Oil layer obtained from prisoners 60. Of was taken, and a hydrogenolysis reaction was carried out in the same manner as in Example 1Ω. The reaction took 75 minutes.

The conversion rate of p-aminoazobenzene was approximately 10,096, but the yield of p-phenylenediamine based on the charged p-aminoazobenzene was 8,796.

Comparative Example 4 (Alkalinizing the p-aminoazobenzene reaction mixture, washing the oil layer with water, leaving it to stand, separating the oil and water, and then hydrogenolyzing it) Comparative Example 3 Oil layer obtained in Example 3 (separated from the reaction mixture) 200 ．． After removing the oil, 80.02 g of water was added, and after shaking with a separating rotor, the mixture was placed to separate oil and water.

Even after 16 hours of standing, there is an intermediate layer in addition to the oil and water layers.
Oil/water separation was insufficient. 16 excluding water layer and middle layer
21 oil layers were obtained.

The concentrations of p-aminoazobenzene and 0-aminoazobenzene in rrf are 25.1wt% and 2.0wt%, respectively.
Met.

■Oil layer obtained in step 4 60. Of was taken, and a hydrogenolysis reaction was carried out in the same manner as in Example 1Ω. The reaction took 1 hour and 20 minutes.

The conversion rate of p-aminoazobenzene was approximately 100%, but the yield of p-phenylenediamine based on the charged p-aminoazobenzene was 92%.

Comparative Example 5 The oil layer obtained in Comparative Example 4(A) was allowed to stand for one week, and from the middle to 60. Of was sampled and used to carry out a hydrogenolysis reaction in the same manner as in Example IQ. 50 for reaction
It took minutes.

The conversion rate of p-aminoazobenzene was 10,096, and the yield of p-phenylenediamine based on the charged p-aminoazobenzene was 98.0%.

The results of Example 1 and Comparative Examples 1 to 5 are summarized in Table 1.

Example 2 (PAAB reaction mixture was alkalized, the oil layer was washed with water, and passed through a normal P paper. After oil and water separation, hydrogenolysis) The oil layer obtained in Comparative Example 3 (the reaction mixture was adjusted to pH 9.
After setting it to 0, let it stand and separate the oil and water +i'))
200. After removing the water, so and or water was added, and the mixture was shaken using a separatory funnel. The mixture turned into an emulsion. The mixture was passed through a Buchner rotor. (F paper used: 7g62 qualitative f paper manufactured by Toyo Roshi).

When the mixture was allowed to stand for a while, the oil and water separated into two layers almost completely within 30 minutes, and compared to Comparative Example 3, it was observed that the oil and water adsorption time was significantly shorter.

The aqueous layer was separated to obtain 196 tons of oil layer.

The concentration in the oil layer is p-aminoazobenzene 23.1wt
%, 0-aminoazobenzene 2.0 wt%.

e) The oil layer 60.Of obtained in (/'J) was then subjected to a hydrocracking reaction in the same manner as in Example 10. The reaction took 1 hour and 20 minutes.

The conversion rate of p-aminoazobenzene is 10096, the charging p
The yield of p-phenylenediamine based on -aminoazobenzene was 94.2%.

Example 5 (t) Synthesis of p-aminoazobenzene p-Aminoazobenzene was synthesized using the same charging ratio and under the same conditions as in Example 1^.

After cooling the reaction mixture obtained in the treated reactor before hydrogenolysis of the 0p-aminoazobenzene synthesis solution! +3wt%NaOH
An aqueous solution was added to adjust the pH to 7.5, and the mixture was then allowed to stand to separate the aqueous layer and oil layer.

775 tons of oil layer was obtained.

401 water was added to this oil layer and mixed. An emulsified mixture was formed, which did not easily separate into an oil layer and an aqueous layer even after being allowed to stand still.

Next, the emulsified mixture was passed through a Buchner funnel using glass fiber 2 paper (G5-25 manufactured by Toyo Kagaku Sangyo Co., Ltd.) under weak suction. Almost no residue remained on the F paper. When the filtrate was allowed to stand still, it separated into an oil layer and an aqueous layer within 10 minutes.

Through such treatment, 775 g of oil layer was obtained. According to gas chromatographic analysis, the concentration of p-7 mino-7zobenzene in the liquid was 23.0 wt%, and the concentration of o+7i-7zobenzene was 2.0 wt%. The p-aminoazobenzene yield based on the sodium nitrite charge was 90.496, o-7
The yield of minoazobenzene is 7,896.

(Q p-7 By hydrogenolysis of mino-7zobenzene
-Synthesis of phenylenediamine@) 60 g of the oil layer obtained in step (2) was sampled within 10 minutes after separation, and reacted and treated in the same manner as in Example 1(C) using the same apparatus.

The reaction was completed in 50 minutes, and gas chromatography analysis revealed that p-phenylenediamine 7.42p and 0-
It was observed that phenylenediamine 0°609 was produced.

This is due to the p-7 present in the solution used for hydrogenolysis.
p-phenylenediamine yield 9a, o96. based on minoazobenzene. Similarly, yield of 0-phenylenedi7mine based on Ko+74no7zobenzene 90.13
It corresponds to 96.

Example 4 (A) (B) Synthesis of p-aminoazobenzene
e: 6 wt96 NaxCOs to adjust the pH of the reaction mixture.
Example 1 except that the pH was adjusted to 8.5 using an aqueous solution and the amount of water added for treatment was 154 g.
Prisoner, perform the reaction in the same way as in (B).

The reaction mixture was worked up. Separation of the oil and water layers was easy.

After the treatment, 772 g of an aniline solution containing 23.1 wt96 p-aminoazobenzene and 2.0 wt96 p-7 minoazobenzene was obtained.

(C) Synthesis of p-phenylenediamine by hydrogenolysis of p-aminoazobenzene Using 7-diphosphorus solution 60.09 of p++74noazobenzene obtained in (B), 0.5 wt% as a catalyst
The reaction and treatment were carried out in the same manner as in Example 1(C), except that 0.14 ml of P (1-silica pellet catalyst (manufactured by Gurhard, Japan) was pulverized into powder.

The reaction was completed in 50 minutes, and gas chromatographic analysis revealed that 7.45 g of p-phenylenediamine and 0.60 g of o-phenylenediamine had been produced.

This result is expressed as a yield based on sodium nitrite.

p-phenylenediamine 88.6%%0-phenylenediamine 7,196, corresponding to a total of 95.5%.

Example 5 (A) (B) Synthesis of p-7ζ-7zobenzene and treatment of reaction mixture Other than adjusting the pH of the reaction mixture to 13.5 and adjusting the amount of water added for treatment to 780 g , Example 1 (
A) The reaction was carried out in the same manner as in (B) and the reaction mixture was treated. Separation of the oil and water layers was easy.

After the treatment, 753 g of an aniline solution containing 23.6 wt96 of p-aminoazopenzey and 2.0 wt96 of Q-7 minoazobenzene was obtained.

(C) p- by hydrogenolysis of p-7 minoazobenzene
Using 60.09 g of the aniline solution of p-7 minoazobenzene obtained in the synthesis (B) of phenylenediamine, the reaction and treatment were carried out in the same manner as in Example 1 (C).

The reaction was completed in 50 minutes, and gas chromatographic analysis revealed that p-phenylenediamine 7°61fI and 0
-Phenylenediamine 0.601 was observed to be produced.

This result corresponds to a total yield of 788.4% for p-phenylenediamine and 7.15% for o-phenylenediamine, which is 95.596% based on sodium nitrite.

Example 6 (A) Synthesis of p-7j-7zobenzene A glass-lined jacketed 5001 reactor equipped with a stirrer was first charged with aniline 223°5-(2,400 moles), then 35°e wt96 concentration. of hydrochloric acid 57.6
2 with 9CHC1.

13.47 odor, 0.369 moles) were added.

After bringing the temperature of this mixture to 18°C, 54.7W was added while stirring and cooling while maintaining the temperature of the contents at 18-20″C.
t96 sodium nitrite aqueous solution 59.66Kp (NaN
20.70 Kg (as 0z, 0.300 mol) was added over 2 hours, and stirring was continued at 20° C. for an additional 15 minutes, resulting in a liquid containing a large amount of yellow slurry.

Next, the temperature was raised to 50°C over about 20 minutes, and a rearrangement reaction was carried out at 48 to 50°C for 1 hour. The reaction solution became a red homogeneous solution. In order to complete the reaction, the temperature was further raised to 70°C and stirred for 15 minutes to complete the reaction.

(B) Treatment before hydrogenolysis of p-7 mino-7zobenzene synthesis liquid The reaction mixture obtained in (A) was cooled and 55wt96N
Approximately 8.4 KF of aOH aqueous solution was added to adjust the pH to 9.0. Next, this mixture was allowed to stand for 2 hours and separated into an oil layer and an aqueous layer, and then the aqueous layer (NaCl aqueous solution) was extracted and separated.

To this oil layer, 45 to 4 water was added and mixed by stirring. An emulsified mixture of 280~ was obtained.

A cartridge (+7'5 m x 75
mx80s+m) filter separator device (coalescer manufactured by Wako Sangyo ■, cartridge material CCX-
111) at a rate of approximately 6011/hr. - It was observed that the liquid that had passed through the filter cartridge was separated into an oil layer and an aqueous layer, and the oil layer and the aqueous layer were separated by allowing the liquid to stand still.

Measurement was carried out for 4 hours under steady operation, and the result was a well-mixed and almost uniform emulsified oil-water mixture 242. o
V4 is fed to the filter separator device and the oil layer
199.2 kg of garlic and 42.8 kg of aqueous layer were obtained separately.

Gas chromatography analysis of the oil layer thus obtained revealed that the concentration of p-7 mino-7zobenzene in the liquid was 23.
．． 1wt96, o-7 minoazobenzene concentration is 3ow
It was t96.

Converting this result to the case of treating the entire amount of oil and water mixture, the yield based on sodium nitrite is p-7 mino-7zobenzene 90
,096.0-7 mino-7zobenzene 7.896, corresponding to a total of 97.8%.

Examples 7 to 10 Using the same apparatus as Example 1(C), each Example 6
(A) Oil layer 60 obtained by the reaction treatment of (B), O
fl was charged, and reactions were carried out in the same manner as in Example 1(C), changing the type of catalyst, the amount used, the reaction temperature, and the reaction pressure.

The reaction time is the time from the start of the reaction at a predetermined pressure until no absorption of hydrogen is observed.

The results are shown in Table 2.

Example 11 The oil layer (aniline solution of p-7 mino-7zobenzene) obtained by the reactions and treatments in Example 6 (A) and (B) was treated using a packed tower type continuous catalytic reduction apparatus.

Feed hydrogenolysis was carried out by contacting with hydrogen and a palladium catalyst.

9-16 mesh grains of 0゜5 wt96Pd supported silica (manufactured by Engelhard Japan) 25d (11,69) as a catalyst in a 16Ml1llll x 500mi+ reactor
211IX3i11 as a preheating part on top of it.
Filled with a porcelain ratchet ring.

While supplying hydrogen from the top of the reactor, the reactor was heated by a heater to bring the temperature of the packed bed to 115°C, and while maintaining the pressure inside the reactor at 7 Kg/cdG, the flow rate of hydrogen gas at the outlet was set to approximately The amount of hydrogen gas supplied was adjusted to 4N/hr. Next, pump approximately 110% of the above aniline solution of p-7 minoazobenzene. ! ? The reaction was started by supplying the solution to the upper part of the reactor at a rate of 1/hr.

Heat generation is seen due to the reaction, but the temperature of the catalyst amount is 120~120℃.
The reaction was carried out at 125° C. while maintaining the hydrogen pressure at about 7.4/cdG.

443g of p-
An aniline solution of 7-mino-7zobenzene is supplied, and during this period it flows out from the reactor outlet and enters the reaction product liquid receiver with >N'E.
The amount of Tsuda reaction product liquid was 444 g. Further, gas from the reactor was discharged to the outside of the apparatus via a reaction product liquid receiver, a cooler, and an outlet gas flow meter.

When this reaction product liquid was analyzed using a gas chromatogram, no residual p-7minoazobenzene and 0-amino7zopenzene were found, and p-phenylenediamine and The concentration is 1 for each
They were 2,4wt96 and t,o5wt96. Almost no other by-products were observed.

The yields based on the p-7mino7zobenzene and o7ino7zobenzene present in the feedstock liquid are
Phenylenediamine 98.11% 10-phenylenediamine 9"6,0546.

Procedural amendment November 8, 1985

Claims (1)

[Claims] Adding an alkaline compound to an aniline solution of p-aminoazobenzene obtained by diazotization coupling of aniline and acid rearrangement reaction to adjust the pH to 7.0 to 13.8,
The oil layer and the water layer are separated, and 0.0% per part by weight is added to the obtained oil layer.
05 to 5.0 parts by weight of water is added and mixed, the mixture is passed through a filter, separated into an oil layer and an aqueous layer, and the resulting oil layer is hydrocracking in the presence of a reducing catalyst. Production method of phenylenediamine